a = 1
s = 0
while a <= 100:
    s += a
    print(f"cuurent number is {a}")
    print(f"current sum is {s}")
    a += 1

# 3. for
str = "Hello Python"
for i in str:
    print(i)

print("----------------------")
# 4. range
for i in range(5):
    print(i)  # 0,1,2,3,4

for i in range(0, 100, 10):
    print(i)

for i in range(5):
    print(i)

# break continue: 只能放在循环里.
print("----------------------")
for i in range(10):
    if i == 5:
        break
    print(i)
